Day 62

The S section finally got to have their half group lesson on radioactivity today. This was the first day 2 I have been in school in a while, and they lost out last week when my back went out. Today, though, they learned what radioactivity is, what an alpha particle, beta particle, and gamma ray are, how it is detected (with a geiger tube and counter--at least that is one way), what causes radioactivity (a ratio of protons to neutrons that is not close to 1), and how to protect yourself from it (shielding, limiting exposure, or running away). They got the chance to see some radioactive rocks and saw a geiger tube and counter in action.

The W and O sections completed lesson 5-2 (see notes for Day 61) and did very well with the kits. The L section moved on and completed lesson 5-3, learning what covalent and metallic bonds are. A covalent bond is a sharing bond, where two atoms share their valence electron/s so that they both have a full shell of 8 (or two with hydrogen). This is different from an ionic bond--in an ionic bond, the electron is transferred, leaving each atom as an ion (a charged atom), and the charge draws them together. A metallic bond is different than both of these. For metals, the nuclei sit in a sea of electrons, which allows the metal to be very malleable, ductile, etc. without breaking like an ionic compound would.

The L's also got a chance to use the kits some more, finishing the first two pages, and making O2 among others. It is a great opportunity for seeing how the bonds create compounds, and why certain compounds exist while others don't.

Sweet justice.

Day 61

This was a fun day for me.  Well, all the days are fun, so this one wasn’t special that way, but I did enjoy it.   The W section got to go through the half-life lab, with more success than the O section had yesterday.  This was because we had technical support from Mr. Nettleton, who not only got all of the Macs running well, but helped me arrange to have several laptop computers so that everyone could have their own computer.  With only a few problems, it worked.  Students got to see the difference between random decay and theoretical decay, something I’ve never found a good way to show before now. 

In full group today, the O section got lesson 5-1 that everyone else got yesterday.  For comments on that lesson, please see Day 60.  They did very well with it.  I also handed their tests back.  The high score for the whole test came from that group—Jeremy Jennings.  He did not miss one question on the Unit 4 test.  Way to go. 

For lesson 5-2, the L and S sections went over the first three essential questions dealing with the importance of valence electrons, how electron dot diagrams work (the dots represent the valence shell electrons surrounding the symbol for the element), and finally, ionic bonds.  An ion is a charged atom, one that has lost or gained electrons.  Make sure you know how an atom becomes positive (loses electrons) or negative (gains electrons).  An ionic bond is formed when a positive ion (usually a metal) attracts to a negative ion (usually a non-metal).  These ionic compounds are usually crystals, brittle, hard, low melting points, and conduct electricity when put in water. 

We also watched a short video, showing the periodic chart like a city, with the highest towers found in the alkali metals and halogens.  Finally, at the end of the period, we got to use the molecular model kits.  Each student gets their own kit to learn more about how bonds form.  We built H₂ today, drew its structural diagram, and also its electron dot diagram. 

In lesson 5-3 we will continue to use the kits, and also learn about two other bond types:  covalent and metallic.  Sweet justice.

Day 60

Today, the O section learned about half-life, and the downsides of technology. First, they signed up for an account with www.explorelearning.com, which was pretty easy to do. Next we attempted to do an activity on half-life, which is a very good one actually, but many of them could not get the shockwave program to work. Half-life is the amount of time it takes for a radioactive element to decay to one-half of its original level. So, if it starts at 100 atoms and has 50 atoms left after 10 seconds, the half-life is 10 seconds.

In full group today, the W, L, and S section began the unit on atoms and bonding. I handed tests back from Unit 4. These were mostly disappointing for me, as too many students did not study at all on their own, relying only on what we did in class. I even posted a version of the test on my moodle site (https://moodle.l-spioneers.org/course/view.php?id=44) that had some of the same questions I asked on the test, but in most classes only one or two students took it. I will be posting the test for Unit 5 soon. Please encourage your son or daughter to take the test!

This is a hard unit. Today we talked about valence electrons (the outermost electrons around an atom with the most energy) and their role in chemical bonding. In fact, these valence electrons are THE reason why bonding happens. The atoms want to be stable, which means getting an outer shell (valence shell) of 8 electrons. They do this through borrowing or sharing electrons. The three types of bonds are ionic, covalent, and metallic. Parents, ask your child to look at their notes and go over them with them. It might help to review the book as well, making sure they understand the concepts.

We also watched a short video on gold, learning about its properties—conductivity, malleability, ductility, little reactivity, soft, dense, and easy to shape (malleable). I gave time in class to work on their homework, which was 5-1, 2, 3. It is due the next full group.

Sweet justice.

Day 59

Today was an unusual day for science, as we spent the day in the library with Mrs. Eberly looking at careers. The students went to the web site www.bridges.com and took some quizzes to discover what their interests and learning styles were. This allowed them to identify some jobs that they would be interested in. This is the second of four sessions the students will be having--social studies, math, and language arts have the other three throughout the school year.

Tomorrow we start Unit 5 on bonding and atoms. This is one of my favorite units of the year, full of exciting demonstrations and surprises.

Day 58

Day 58--Tuesday, November 23, 2007

Unfortunately, I was not in school today--I threw my back out over the weekend and spent the day crawling around on the floor. In school, the O, W, and S sections took their Unit 4 tests on elements and the periodic table. The test is a combination of multiple choice, true and false, short answer, and essay questions. The L section, who took their test yesterday, watched a video on explosions and fire, a topic which leads us into our next unit on chemical reactions and bonding.

This is also the day before Thanksgiving break. Sweet justice.